Drill bit



E. G. BOICE Oct. 18, 1955 DRILL BIT 2 Sheets-Sheet 1 Filed Sept. 16, 1948 E/V/n 6. BO/ce IN vnvron U m a Y M TTOR/VEYJ Oct. 18, 1955 Filed Sept. 16, 1948 E. G. BOICE DRILL BIT 2 Sheets-Sheet 2 E/l/m 6. Home A T TORNE YJ' United States Patent DRILL BIT Elvin G. Boice, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application September 16, 1948, Serial No. 49,485

3 Claims. (Cl. 255-61) This invention relates generally to deep well drilling apparatus and particularly to the mounting of slush nozzles in drill bits.

In the drilling of deep wells, a mud laden fluid called slush is pumped down through the drill stem and through slush openings in the bit at the bottom of the drill stem, returning to the surface of the earth in the space between the drill stem and the wall of the hole.

Slush, pumped at high pressures, is very abrasive, and in order to prevent abrasion of the walls of the slush openings in the bit, abrasion resisting slush nozzles are mounted in the openings. Such nozzles are welded or brazed in the slush openings in the bit head.

There are a number of ceramic materials and other metal alloys which, by virtue of their capacity to resist abrasion, would be ideally suited for slush nozzles, but unfortunately materials of this nature cannot be welded or brazed in the slush openings of the bit head.

This invention has for one of its objects the provision of a new and improved method and apparatus whereby slush nozzles made of ceramic and unweldable alloys may be readily secured in the slush openings of a bit.

Other objects will hereinafter appear.

In the accompanying drawings in which two preferred embodiments of the invention are illustrated:

Fig. l is a sectional view of the apparatus employed for stretching the nozzle securing sleeve on the nozzle;

Fig. 2 is a horizontal section on the line 22 of Fig. 1;

Fig. 3 is a view illustrating the nozzle securing sleeve stretched on the nozzle and inserted in the slush opening in the bit.

Fig. 4 illustrates the nozzle secured in place in the slushing opening in the bit.

Fig. 5 is a view similar to Fig. 4 and it illustrates another embodiment of the invention.

Referring to Fig. 4 of the drawings, the bit is indicated at 1, the slush opening in the bit at 2, the abrasion resisting slush nozzle at 3 and the elastic sleeve securing the nozzle in place at 4. The slush pumped downwardly through the drill stem to the bit 1 enters the chamber 1-a and passes outwardly through the bore of the nozzle 2.

The bit 1 may be made of steel, the nozzle 3 of abrasion resisting ceramic material or other metal alloy and the elastic sleeve 4 of rubber.

Referring now to Fig. 1, the sleeve 4 is shown in its normal condition on the nozzle 3 and secured to an apparatus including a mandrel 5 by means of the clamp 6 which is made in two sections held together by bolts 7. The inner surface of the clamp 6 is serrated as indicated at 8 and the exterior surface of the mandrel is serrated as indicated at 9, whereby the end 4-a of the sleeve 4 is securely connected thereto.

The numeral 10 indicates a shaft threaded in the mandrel 5 and having an external flange 11 resting on the top of the nozzle 3 and a pilot 12 extending into the 2,721,058 Patented Oct. 18, 1955 nozzle 3. It will be apparent that when the shaft 10 is rotated, the mandrel 5, carrying with it the lower end of the sleeve 4, will be moved from the position shown in Fig. 1 to the position shown in Fig. 3, away from the nozzle 3. The rubber sleeve 4 will be thereby stretched as indicated and the nozzle 3 with the stretched sleeve 4 thereon may be inserted in the slush opening 2 of the bit 1 as shown by Fig. 3. Then the shaft 10 may be rotated in the reverse direction which will cause the mandrel 5 to approach the nozzle 3 which will allow the elastic sleeve 4 to expand outwardly in the opening 2 to firmly secure the nozzle 3 in said opening. After the mandrel 5 has been moved to the flange 11, the rubber extending from the opposite ends of the opening 2 in the bit head may be trimmed off and the shaft 10, mandrel 5, and clamp 6 removed so that the nozzle 3 will remain mounted in the opening 2 of the bit as shown by Fig. 4.

As shown by Fig. 5, the wall of the tapered opening 2-a may be provided with grooves 2-b and the exterior of the tapered nozzle 3-a with grooves 3b, said grooves being for the reception of the sleeve 4a when it is released after being stretched as indicated in Fig. 3. Any increase in mud pressure in the chamber 1a will result in a further seating and sealing of the rubber retainer 4a due to the taper in the bore of 2a and the taper on the exterior of the nozzle 3a.

The invention is not limited to the preferred embodiments herein disclosed. Various changes within the scope of the following claims will be apparent to those skilled in the art.

I claim:

1. A drill bit having a slush opening therein, a tubular slush nozzle disposed within said opening, and a separate tubular elastic sleeve element unconnected with the nozzle and interposed between the exterior of the nozzle and the wall of the opening, said sleeve having a normal Wall thickness greater than the annular space between the nozzle and the wall of the opening when unconfined, but said sleeve being confined within said space of lesser thickness than said normal wall thickness in a stretched or extended conditions, whereby the inherent elasticity of the sleeve element in its confined condition tends to return the element to its unconfined normal shape and thereby applies a frictional gripping force to the exterior of the nozzle to maintain the same in position within the slush opening.

2. A drill bit as set forth in claim 1, wherein the exterior wall of the nozzle and the wall of the opening are provided with annular grooves within which the portions of the elastic sleeve element are engaged.

3. A drill bit as set forth in claim 1, wherein the exterior wall of the nozzle and the wall of the opening are provided with annular grooves within which the portions of the elastic sleeve element are engaged, and also wherein the exterior of the nozzle and wall of the opening are tapered.

References Cited in the file of this patent UNITED STATES PATENTS 701,101 Stutz May 27, 1902 712,514 Erickson Nov. 4, 1902 1,369,544 Renfro Feb. 22, 1921 1,589,633 Dunton et al. June 22, 1926 2,017,834 Hummel Oct. 15, 1935 2,055,144 Christian Sept. 22, 1936 2,100,615 Snell Nov. 30, 1937 2,110,783 Welker Mar. 8, 1938 2,252,299 McCoy Aug. 12, 1941 2,408,892 Stokes Oct. 8, 1946 

